Porto have reportedly rejected the opportunity to be reunited with Manchester United defender Diogo Dalot before the end of the summer transfer window.
The Premier League giants are currently bidding to sign Porto left-back Alex Telles but the two clubs are yet to agree a fee for the attack-minded defender.
According to O Jogo, that has led to United proposing the idea of Dalot being included in a part-exchange deal for the Brazilian.
Dalot, who left Porto to move to Old Trafford in 2018, has fallen down the pecking order since the appointment of Ole Gunnar Solskjaer.
However, the report claims that the Portuguese giants are not interested in handing the 21-year-old a second spell at Estadio do Dragao.
United may have to make a £20m bid in order to get a deal for Telles over the line.